Emblems are like awards for completing levels, Chao Races, Chao Karate Etc. When You unlock all 180 of 'em you get a 3-D version of Green Hill Zone!
You need to have at least iver 25 emblems to get a green egg in sonic adventure 2 battle
170 or 180
Collect emblems
Get a lot of emblems
Collect emblems
100.
Collect a lot of emblems
100
20
50 or 40
100
go buy the light blue egg RE:: After 105 emblems.